'George Mallory conquered Everest decades before Sir Edmund Hillary'

A mountaineering expert will today claim that Sir Edmund Hillary was not the first man to scale Everest - and that it was in fact conquered three decades before by the British climber George Mallory.

Graham Hoyland has spent years researching a story he was told as a boy: Mallory, who took part in the first three British expeditions and who is widely accepted as having just failed to reach the summit, did in fact succeed and was on his way down when he died.

Mallory and his climbing partner, Andrew Irvine, both went missing somewhere high on the north-east ridge during the final stage of their attempt to make the first ascent of the world's highest mountain in June 1924.

The pair's last known sighting was only 800ft from the summit and Mallory's body lay undiscovered for 75 years. It has never been proved whether they were on their way up, or had completed the climb and were on their way down.